Add option for Softphone to existing program to dial customers direct from program

I have an existing program (with source) that I want to be able to press a button to call the customer from that screen thru Voip (softphone or initiate call thru physical Voip Phone) - Code Must be in Delphi - Must be in nice GUI - Release of payment only after program is bug free - Must provide full source code and all components used so we can recompile if needed